TM are always almost entirely abs plastic due to Japanese laws. There are metal slides and metal kits, but at least for the pistols the kits are quite rare in country since they're restricted and will jack the price of the pistol up considerably. Slides on the other hand aren't restricted so they're fairly common, still not the cheapest thing in the world but nothing approaching the cost of a kit.

Unfortunately pretty much all the good pistol makers are in Japan so all the really good pistols are going to be abs plastic.

Edit: $180 for a full metal TM DE? not a chance in living hell. Even a stock all plastic TM DE is going to cost nearly three times that amount.